ES51970(6000counts)
DMM Analog front end with Inrush
2.10 Inrush measurement
F3
1
F2
0
F1
0
F0
1
AC
1
Measurement mode Input terminals Read data bytes
ADP AC mode
ACA mode
ADP
D0(0:18)
D0(0:18)
0
0
1
0
1
IVSH/IVSL
ES51970 provides an inrush function for AC current measurement of clamp-on meter to
dectect the starting-up current of a motor. Only ACA/ADP(AC) modes support inrush
measurement mode. SET control bit INA=1 of write command to enter the inrush function.
Initially, the status bit ALARM=1 means to wait for signal triggered (> 20mVp typ.). If the
external starting-up signal is applied and detected, ES51970 will execute the inrush
measurement. When the inrush measurement is finished, the status bit F_FIN=1 to indicate
the inrush integration cycle is finished. It means the ADC data is ready for access by MCU.
To enter inrush mode cycle again, set control bit INA=1 of write command and repeat the
procedures mentioned above. To exist inrush mode, set INA=0 of write command. For
INRUSH function, an external true RMS-to-DC ES636 IC is required. The flow chart of
inrush function is shown below.
ver. 2.8
22
12/01/12
CYRUSTEK [ Cyrustek corporation ]
